Carburetor



H. A. CRAFT June 29, 1965 CARBURETOR 2 Sheets-Sheet 1 Filed Dec. 13,1965 INVENTOR. #44144 0 4, [cw-r June 29, 1965 H. A. CRAFT CARBURETORFiled Dec. 13, 1965 2 Sheets-Sheet 2 INVENTOR. firm/w 4 (luff W WWWUnited States Patent 1963, Ser. No. 330,329

The invention relates generally to carburetors and like devices forinducing a fluid flow in response to a pressure condition below thesurrounding or atmospheric pressure condition.

The invention can be embodied in any arrangement including a conduit orpassage such as the throat of a carburetor, a fluid reservoir such asthe fuel bowl of a carburetor, and conduit means communicating betweenthe conduit or passage and the fluid reservoir below the part thereofnormally occupied by the fluid. In such an arrangement, when thepressure condition in the conduit or passage is less than the pressurecondition in the part of the fluid reservoir unoccupied by fluid, fluidflow is induced from the reservoir through the conduit means to thepassage. The invention provides for valve means and associated passagemeans for automatically establishing communication between the part ofthe fluid reservoir normally unoccupied by fluid and the atmosphere, andbetween the part of the reservoir normally unoccupied by fluid and thepassage by means other than the before mentioned conduit means. In thefirst instance, when the reservoir is in communication with theatmosphere, a pressure condition in the passage lower than atmosphericis effective to draw fluid from the reservoir through the conduit meansand into the passage. In the other instance, the part of the reservoirnormally unoccupied by fluid is closed off from the atmosphere and,instead, is placed in communication with the passage. Consequently, thebody of fluid in the reservoir is subject to the same pressure conditionacting through the conduit means and acting on the surface of the fluidin the reservoir. Flow through the conduit means to the passage istherefore no longer generated.

In the case of an internal combustion engine which is supplied acombustible measure of fuel and air from an associated carburetor, useof a carburetor incorporating the above disclosed arrangement assuresdiscontinuance of engine operation when the atmosphere above the fuel inthe fuel bowl is placed in communication with the throat of thecarburetor, thereby cutting off further fuel flow to the engine. This isparticularly important in high speed engines which may have a tendencyto continue operation even after the ignition is turned off.

The invention also provides for a carburetor having electricallycontrolled valve means and for an internal combustion engine includingboth an ignition system and such a carburetor, which carburetor iselectrically integrated with the ignition system. Thus, in the disclosedembodiments, the carburetor valve means is solenoid actuated and thesolenoid is integrated with the ignition system so that, in response toturning off of the ignition, fuel flow through the carburetor from thefuel bowl to the throat and subsequently to the engineis prevented. Theinvention further provides for a carburetor which can be assembled toselectively provide for preventing engine operation either when thesolenoid is energized or de-energized.

The invention also contemplates connection of the carburetor valve meanswith remote actuating means to cause discontinuance of engine operationby preventing .fuel flow thereto, notwithstanding continued normaloperation of the ignition system as for instance, in the event of engineoverheating.

Other objects and advantages of the invention will become known byreference to the following drawings and accompanying description inwhich:

FIGURE 1 is a schematic view of an engine incorporating various of thefeatures of the invention;

FIGURE 2 is a sectional view of the carburetor shown in FIGURE 1, thecarburetor being shown in the condition permitting engine operation whenthe solenoid therein is de-energized;

FIGURE 3 is a fragmentary view of the carburetor shown in FIGURE 2, thecarburetor being shown in the condition preventing engine operation inresponse to energizing of the solenoid;

FIGURE 4 is a diagrammatic view showing an engine ignition circuitusable with the carburetor shown in FIG- URES 2 and 3;

FIGURE 5 is a sectional view of the carburetor of FIGURES 3 and 4, shownassembled to permit engine operation when the solenoid is energized andwith the solenoid in energized condition;

FIGURE 6 is a fragmentary view of the carburetor shown in FIGURE 5, thecarburetor being in the condition preventing engine operation When thesolenoid is deenergized; and

FIGURE 7 is a diagrammatic view showing an engine ignition circuitusable with the carburetor shown in FIG- URES 5 and 6.

The engine 11 shown in FIGURE 1 can be of any conventional construction,including an engine block 12 with a cylinder 13 having a spark plug 15mounted therein, together with an ignition system comprising an ignitioncircuit including a breaker mechanism 17. Also included in the engine 11is a carburetor 19 which supplies carbureted air to the cylinder 13 in aconventional manner and which is constructed to include various of thefeatures of the invention. The carburetor 19, as shown best in FIGURES 2and 3, includes a plunger or member 21 which is displaceable between twopositions respectively preventing and permitting engine operation.Normally, the plunger 21 is biased toward one position and can be movedor displaced to the other position either manually or, as in thepreferred construction, by electrical operating means in the form of asolenoid. One of the advantages of the disclosed construction is thatthe carburetor can be arranged either to prevent or to permit engineoperation when in its biased position in accordance with the manner inwhich the carburetor components are assembled.

The carburetor 19 comprises a housing 23 including a duct which includesa throat or portion 25 subject to pressure conditions below atmosphericand which includes the usual throttle valve 27. Supported by the housing23 is a fuel reservoir or bowl 29 which communicates with a source offuel through a threaded socket 31 and includes the usual float valve 33.Except for connection with conduit means in the form of one or moreorifices or jets 34 which are shown schematically in broken lines inFIG- URE 2 and which communicate with the throat 25 for supplying fuelthereto in accordance with the vacuum condition existing therein, andexcept as otherwise explained hereinafter, the reservoir 29 is closed.The pro- .vision of the orifices or jets 34 is well known, as shown forinstance in the Evinr'ude Patent No. 2,744,736.

One of the features of the invention resides in the provision of valvemeans operable to establish communication between the reservoir 29 at apoint above the normal fuel level therein and either of the atmosphereand the throat 25, such communication between the throat 25 and thereservoir 29 being by means other than the jets or orifices normallyaffording fuel flow from the reservoir 29 to the throat 25.

When the reservoir 29 is in communication with the o (is atmosphere,engine operation takes place in the normal manner. However, when thereservoir 29 is in communication with the throat 25, the pressurecondition existing in the throat 25 also acts on the surface of the fuel1n the reservoir 25, thereby preventing further fuel flow through thejets to the throat 25. Engine operation is therefore renderedimpossible. This is of particular importance with respect to enginesincluding ignition systems having a tendency to continue to sustainignition even though the usual ignition switch is in its ofi position.

The. means for selectively establishing communication between thereservoir 29 and either of the throat 25 and the atmosphere includesprovision in the housing of a passage or bore 35 communicating at oneend with the reservoir 29 at a point above the normal surface of thefuel in the bowl. Communicating with the bore 35 are a pair oftransverse passages 37 and 39 which are spaced axially or the bore 35and extend from the exterior of the housing Q6 and communicate with thethroat 25.

Extending in the bore 35 is a selectiveblocking means in the form of ahollow guide or sleeve 41 which, at its upper end, supports the yoke 43of a conventional solenoid 4 5. At its lower end, the sleeve 41 includesa transverse aperture 47 adapted to receive a screw 49 utilized tofixedly assembly the guide 1'1 and connected solenoid 45 to the housing23. The sleeve 41 also includes a pair of diametrically opposed ports 51and 53 which are spaced axially of the bore from one another by anamount corresponding to the spacing between the passages 37 and 39 andwhich are located in relation to the length of the sleeve 41 in positionfor communication with the passages 37 and 39 when the sleeve 11. isproperly assembled in the bore 35.

I Slideably mounted in the sleeve 41 is the elongated member 21 whichcomprises the armature of the solenoid 4-5 and which is biased away fromthe solenoid 45 by a spring 55, such movement being limited by a stop 57secured within the sleeve 41. Extending in and from the lower end of thearmature or member 21 is an axial bore 59 terminating in a cross bore 61located for communication with the port 51 when the armature 2.1 islocated with its lower end engaged with the stop 57.

In the arrangement shown in FIGURE 2, the carburetor solenoid 45 iselectrically connected in the ignition circuit 53 shown diagrammaticallyin FIGURE 4. The carburetor 19, as shown in FIGURE 2, is arranged toallow engine operation when the solenoid 45 is deenergized and toprevent fuel supply to the engine when the solenoid 45 is energized.

More specifically, in the arrangement shown in FIG- URE 2, the sleeve d1is assembled so that the port 53 communicates with the portion 39a ofthe passage 39 extending between the bore 35 and the throat 25 and sothat the port 51 cornunica-tes with the portion 37b of the passage 37extending between the bore 35 and the exterior of the housing. Thus,when the solenoid 45 is de-energized, the armature 21 is positioned bythe spring 55 against the stop 57 to establish communication between thesurface of the fuel in the reservoir 29 and the atmosphere through thepassage portion 37b, the port 57, the cross bore 61, the axial bore 59in the armature 2/1, and the open interior of the sleeve 41. At the sametime, the passage portions 37a and 5% are blocked by the sleeve 41,while the passage portion 35a which communicates with the port 53 isblocked by the outer wall of the armature 21. As both passage portions37a and 39a communicating with the throat 25 are blocked, normal engineoperation is therefore permitted.

ment of the armature 2.1 closes communication between the passageportion 371) and the reservoir 29 while establishing communicationbetween the reservoir 29 and the jets.

carburetor throat 25 through the hollow interior of the sleeve 41, theport 53, and the passage portion 39a. The surface of the fuel in thereservoir is therefore subject to the pressure condition existing in thecarburetor throat 25, thereby precluding further fuel ilow through theorifices or In addition, communication between the reservoir 29 and theatmosphere through the passage portion 57b and port '51 is blocked bythe outer wall of the armature 2'1. 7

The circuit s3 shown in FIGURE 4 includes both a magneto ignitioncircuit 64 and a solenoid actuating circuit 55. The magneto ignitioncircuit 64 includes a coil having primary and secondary windings 66 and67, respectively. As is usual, the secondary winding 67 is grounded atone end and, at its other end, is connected to the spark plug 15. At oneend, the primary winding 66 is connected in parallel to a breaker 69 anda condenser 71. At its other end, the primary winding 65 is connectablethrough one pole of a double pole switch 73 to a ground 74.

Also extending through the double pole switch 73 is the sub-circuit 65including the winding in the solenoid 45 and a battery 75. The switch 73couples the solenoid 45 and the ignition system so that when the magnetoignition circuit 64 is closed to permit normal engine operation, thecircuit 65 to the solenoid 45 is open. However, when the switch 73 isactuated to interrupt or open the magneto circuit 64, the circuit 65 tothe solenoid 45 is closed. The circuit 63 shown in FIGURE 4 can also beused in a battery ignition system by connecting the ignition circuit 64to the battery 75.

In the arrangement shown in FIGURES 5 and 6, the sleeve 41 is located inthe bore 35 so that the port 51 communicates with the passage portion37a and so that the port 53 communicates with the passage portion 3%.Both of the passage portions 37b and 3% are blocked by the sleeve 41.With this arrangement, normal engine operation is permitted when thesolenoid 45 is energized by affording communication between thereservoir 29 and the atmosphere through the passage portion 3%, the port53, and the interior of the sleeve 41. When the solenoid 45 isde-energized, the armature 21 engages the stop 57, blocking the port 53and establishing communication between the port 51 and the cross bore61. As a result, communication between the reservoir and the atmosphereis blocked and, instead, the reservoirr29 communicates with thecarburetor throat 25 through the passage portion 37a, the port 51, thecross bore 61, the axial bore 5h in the armature Z1, and the interior ofthe sleeve 41, thereby preventing further fuel flow. a

The carburetor 19, as shown in FIGURES 5 and 6, can be used inconnection with the ignition circuit 163 shown in FIGURE 7. This circuitincludes both a magneto subcircuit 164 and a solenoid operatedsub-circuit 165. The magneto circuit 164 includes a coil having primaryand secondary windings 166 and 167, respectively. The sec ondary winding167 is grounded at one end and connected to the spark plug 15 at itsother end. The primary winding 166 is grounded at one end and, at itsother end, is connectable through one pole of a double pole switch 173to a ground 174. Wired in parallel with the primary winding 166 is abreaker 159 and condenser 171. In the circuit 163 shown in FIGURE 7, thedesired sparking will be provided when the switch 173 is closed.However, when the switch 173 is opened, the primary winding 166 will bedisconnected from the ground 174, thereby preventing sparking operationin response to operation of the breaker 169. V

The switch 173 also controls the solenoid'operating circuit 1&5. whichincludes the solenoid 45 and a battery 175. The switch 173 is arrangedso that when the primary winding 166 is connected tothe ground 174,'thecircuit is closed, thereby energizing the solenoid 4-5 and permittingengine operation. However, when the switch 173 is operated to open theignition circuit 164, the circuit 165,

to the solenoid 45 is also opened, thereby 'de-energizing the solenoid45 to prevent further engine operation. The circuit 163 shown in FIGURE7 can be modified to permit battery operation of the ignition circuit164by passing both the solenoid operating circuit 165 and the ignitioncircuit 164 through a single switch which, when closed, connects boththe primary winding 166 and the solenoid 45 in series with the battery175.

Various of the features of the invention are set forth in the followingclaims.

What is claimed is:

1. The combination of a duct having a portion subject to a pressurecondition below atmospheric, a closed fluid reservoir, conduit meanscommunicating with said fluid reservoir below the part thereof normallyoccupied by the fluid and with said duct portion so as to be subject tothe pressure condition in said duct portion, first passage meanscommunicating with said fluid reservoir above the part thereof normallyoccupied by the fluid, second passage means communicating with said ductportion so as to be subject to said same pressure condition to whichsaid conduitmeans is subject, vent means communicating with theatmosphere, and valve means communicating with said first and saidsecond passage means and with said vent means for alternatively andselectively establishing communication between said first passage meansand said vent means and between said first passage means and said secondpassage means, whereby, when said first passage means communicates withsaid vent means, flow of fluid is afforded from said fluid reservoirthrough said conduit means to said duct in response to a pressurecondition in said duct portion below atmospheric, and when said firstpassage means communicates with said second passage means, flow of fluidfrom said reservoir through said conduit means to said duct terminates.

2. A carburetor including a housing comprising means defining a throat,a closed fuel reservoir adapted to be connected to a source of fuel,means connected with said reservoir for maintaining a generallypredetermined fuel level in said reservoir, fuel conduit meanscommunicating with said reservoir below said fuel level and terminatingin said throat for delivering fuel to said throat in response to thepresence of a condition of lesser pressure in said throat than on thesurface of the fuel in said reservoir, a first passage communicatingwith said reservoir above said fuel level, a second passagecommunicating with said throat, a third passage communicating with theatmosphere, and valve means communicating with said first, second, andthird passages for alternatively and selectively establishingcommunication between said first passage and one of said second andthird passages.

3. A carburetor in accordance with claim 2 wherein said valve meansincludes a member movable relative to said first, second, and thirdpassages, and means for displacing said member between a first positionwherein communication is blocked between said first passage and saidsecond passage and communication is estabilshed between said firstpassage and said third passage for gas flow between the atmosphere andsaid reservoir, and a second position wherein communication between saidfirst passage and said third passage is blocked and communication isestablished between said first passage and said second passage for gasiiow between said throat and said reservoir.

4. A carburetor in accordance with claim 3 wherein said means fordisplacing said member comprises an electrical solenoid.

5. A carburetor in accordance with claim 4 including means biasing saidmember toward said first position, and wherein said electrical solenoidis energizable to displace said member to said second position. a

6. A carburetor in accordance with claim 4 including means biasing saidmember toward said second position, and wherein said electrical solenoidis energizable to displace said member to said first position.

7. A carburetor including a housing comprising means defining a throat,a closed fuel reservoir adapted to be connected to a source of fuel,means connected with said reservoir for maintaining a generallypredetermined fuel level in said reservoir, fuel conduit meanscommunicating with said reservoir below said fuel level and terminatingin said throat for delivering fuel to said throat in response to thepresence of a condition of lesser pressure in said throat than on thesurface of the fuel in said reservoir, a first passage communicatingwith said reservoir above said fuel level, a second passagecommunicating with said throat and including a bore communicating withsaid first passage, a third passage communicating with the atmosphereand including an opening communicating with said first passage, andvalve means communicating with said first, second, and third passagesfor alternatively and selectively establishing communication betweensaid first pas sage and one of said second and third passages, saidvalve means including amember movable in said first passage, said memberhaving an outer surface, a cavity extending in the direction ofmovement, said cavity being open at the end of said member adjacent tosaid reservoir and being closed at the other end, and a port in the.outer surface of said member communicating with said cavity, and meansfor displacing said member between a first position whereincommunication between said first passage and said bore is blocked bysaid outer surface and said port conununicates with said opening for gasflow between the atmosphere and said reservoir, and a second positionwherein said opening is blocked by said outer surface and said firstpassage is in communication with said bore.

8. A carburetor including means defining a throat, a closed fuelreservoir adapted to be connected to a source of fuel, means connectedwith said reservoir for maintaining a generally predetermined fuel levelin said reservoir, fuel conduit means communicating with said reservoirbelow said fuel level and terminating in said throat for delivering fuelto said throat in response to the presence of a condition of lesserpressure in said throat than on the surface of the fuel in saidreservoir, a first passage communicating with said fuel reservoir abovesaid fuel level, second and third passages communicating with said firstpassage and with the exterior of said housing, fourth and fifth passagescommunicating with said first passage and with said throat, means forselectively blocking one of said second and third passages and one ofsaid fourth and fifth passages, and valve means communicating with theother of said second and third passages and with the other of saidfourth and fifth passages for alternatively and selectively establishingcommunication between said reservoir and one of said throat and theexterior of said housing.

9. A carburetor including means defining a throat, a closed fuelreservoir connected to a source of fuel, means connected with saidreservoir for maintaining a generally predetermined fuel level in saidreservoir, fuel conduit means communicating with said reservoir belowsaid fuel level and terminating in said throat for delivering fuel tosaid throat in response to the presence of a condition of lesserpressure in said throat than on the surface of the fuel in saidreservoir, a first passage communicating with said reservoir above saidfuel level, a second passage communicating with said first passage andincluding a first portion communicating with the atmosphere, and asecond portion communicating with said throat, a third passagecommunicating with said first passage and including a first portioncommunicating with the atmosphere and a second portion communicatingwith said throat, means for blocking said first portion of a selectedone of said second and third passages and said second portion of theother of said second and third passages, and valve means communicatingwith said first portion of said other of said second and third passagesand with said second portion of said one of said second and thirdpassages for alternatively and selectively establishing communicationbetween said reservoir and one of said throat andthe atmosphere.

10. A carburetor in accordance with claim 9 wherein said blocking meanscomprises a sleeve received in said first passage and having a firstport in registry with said first portion of said other of said secondand third passages, and a second port in registry with said secondportion of said one of said second and third passages.

ill. A carburetor in accordance with claim 10 wherein said valve meansincludes a member movable reciprocably in said first passage,said'member having an outer surface, a cavity extending in the directionof reciprocal movement, said cavity being open at the end of said memberadjacent to said reservoir and being closed at the other end, and a portin the outer surface of said member communicating with said cavity, andmeans for displacing said member between a first position whereincommunication between said first passage and said second port is blockedby said outer surface and said reservoir communicates with theatmosphere, and a second position wherein communication between saidfirst passage and said first port is blocked by said outer surface andsaid reservoir is in communication with said throat.

12. The combination of an engine having an ignition system and acarburetor having a throat, a closed fuel bowl connected to a source offuel, means for maintaining a generally predetermined fuel level in saidbowl, fuel conduit means communicating with said fuel bowl below saidfuel level and with said throat, a first passage communicating with saidfuel bowl above said fuel level, a second passage communicating withsaid throat, a third passage communicating with the atmosphere, valvemeans communicating with said first, second, and third passages foralternatively and selectively establishing communication between saidfirst passage and said second passage and between said first passage andsaid third passage, said valve means including electrical operatingmeans, and means electrically coupling said electrical operating meansand said ignition system for operating said valve means in accordancewith the operation of said engine.

13. A combination in accordance with claim 12 wherein said valve meansfurther includes a member movable by said electrical operating meansrelative to said first, second, and third passages, and between a firstposition 8 affording engine operation wherein communication is blockedbetween said first passage and said second passage and communication isestablished between said first passage and said third passage for gasflow between the atmosphere and said fuel bowl, and a second positionprecluding engine operation wherein communication between said firstpassage and said third passage is blocked and communication isestablished between said first passage and said second passage for gasflow between said fuel bowl and said throat. I I

14. A combination in accordance with claim 13 wherein said electricaloperating means comprises an electrical solenoid.

15. A combination in accordance with claim 14 including means biasingsaid member toward said position atfording engine operation and whereinsaid means electrically coupling said electrical operating means andsaid ignition system energizes said solenoid to displace said member tosaid position precluding engine operation in response to interruption ofsaid ignition system.

l. A combination in accordance with claim 14 including means biasingsaid member toward said position precluding engine operation and whereinsaid means electrically coupling said electrical operating means andsaid ignition system energizes said solenoid to displace said member tosaid position affording engine operation in response to conditioning ofsaid ignition system for engine operation.

References Cited by the Examiner UNITED STATES PATENTS 0 2,905,013 9/59Goetz 261-72 3,080,858 3/63 Kane 123-97 FOREIGN PATENTS 74,031 11/60France.

(Addition to 1,087,311) 1,086,943 8/60 Germany.

RICHARD B. WILKINSON, Primary Examiner.

KARL I. ALBRECHT, Examiner.

1. THE COMBINATION OF A DUCT HAVING A PORTION SUBJECT TO A PRESSURECONDITION BELOW ATMOSPHERIC, A CLOSED FLUID RESERVOIR, CONDUIT MEANSCOMMUNICATING WITH SAID FLUID RESERVOIR BELOW THE PART THEREOF NORMALLYOCCUPIED BY THE FLUID AND WITH SAID DUCT PORTION SO AS TO BE SUBJECT TOTHE PRESSURE CONDITION IN SAID DUCT PORTION, FIRST PASSAGE MEANSCOMMUNICATING WITH SAID FLUID RESERVOIR ABOVE THE PART THEREOF NORMALLYOCCUPIED BY THE FLUID, SECOND PASSAGE MEANS COMMUNICATING WITH SAID DUCTPORTION SO AS TO BE SUBJECT TO SAID SAME PRESSURE CONDITION TO WHICHSAID CONDUIT MEANS IS SUBJECT, VENT MEANS COMMUNICATING WITH THEATMOSPHERE, AND VALVE MEANS COMMUNICATING WITH SAID FIRST AND SAIDSECOND PASSAGE MEANS AND WITH SAID VENT MEANS FOR ALTERNATIVELY ANDSELECTIVELY ESTABLISHING COMMUNICATION BETWEEN SAID FIRST PASSAGE MEANSAND SAID VENT MEANS AND BETWEEN SAID FIRST PASSAGE MEANS AND SAID SECONDPASSAGE MEANS, WHEREBY, WHEN SAID FIRST PASSAGE MEANS COMMUNICATES WITHSAID VENT MEANS, FLOW OF FLUID IS AFFORDED FROM SAID FLUID RESERVOIRTHROUGH SAID CONDUIT MEANS TO SAID DUCT IN RESPONSE TO A PRESSURECONDITION IN SAID DUCT PORTION BELOW ATMOSPHERIC, AND